Electronic modules, such as circuit boards, generally have peripheral components, such as converters, to couple to external ports. Because of differences in port types, the converters need to be easily removable to couple to different port types. After the electronic module is fixed in a mounting device, the mounting device is slidably mounted to a rack. All-in-one type mounting devices are generally inconvenient for disassembling peripheral components, and modular type mounting devices generally have complex structures for disassembling peripheral components.